1. Field of the Invention
The present invention relates to a non-conjugated cyclic diene, a non-conjugated cyclic diene composition and a method of producing a polymer based on non-conjugated cyclic diene.
2. Description of the Related Art
Polymers based on non-conjugated cyclic diene such as ethylene/propylene/ethylidene norbornene copolymers are those which are vulcanizable, are superior in weatherability, heat resistance and ozone resistance and are used for automobile industrial parts, industrial rubber products, insulating materials, civil and construction materials and rubber products such as gummed clothes and also widely used for materials to be blended with plastics such as a polypropylene and polystyrene. In the case of manufacturing such a polymer based on non-conjugated cyclic diene, there is the case where polymerization activity is low though this depends on manufacturing conditions such as catalysts. Therefore it has been desired to develop a method of producing a polymer based on non-conjugated cyclic diene at a high degree of polymerization activity.
Under this situation, the applicant of this case has proposed a method using norbornene or its derivative which are brought into contact with alumina or norbornene or its derivative which are brought into contact with an aqueous alkali as a raw monomer when manufacturing a polymer based on non-conjugated cyclic diene by using a metallocene type catalyst (see JP-A No. 2000-204120).
A refining method is proposed in which when dicyclopentadiene is used in reaction-injection molding, it is brought into contact with an alkali material, followed by washing with water and dewatering (see JP-A No. 01-096410). However, in the method described there, a polymer cannot be obtained at a high degree of activity when polymerizing or copolymerizing a non-conjugated cyclic diene by using a specific catalyst system such as a metallocene type catalyst.
The inventors of the present invention have made further studies, and as a result, found that a specific component contained in a non-conjugated cyclic diene inhibits polymerization when a specific catalyst component such as an organic aluminum oxy compound and/or ionizing ionic compound is used to polymerize or copolymerize a non-conjugated cyclic diene, and when a non-conjugated cyclic diene reduced in the amount of that component to lower than a specific level is used, the activity of polymerization is significantly increased in the polymerization and copolymerization of the non-conjugated cyclic diene by using a specific catalyst component containing an organic aluminum oxy compound and/or ionizing ionic compound, to complete the present invention.
The inventors have also found that when using a non-conjugated cyclic diene obtained by a specific method in which a crude non-conjugated cyclic diene is brought into contact with an alkali and then a low-boiling point fraction and/or a high-boiling point fraction are removed, the activity of polymerization is significantly increased in the polymerization and copolymerization of the non-conjugated cyclic diene by using a specific catalyst component containing, for example, an organic aluminum oxy compound and/or ionizing ionic compound, to complete the present invention.